The effect of complement and other cell wall reagents on tetracycline and streptomycin resistance in Pseudomonas aeruginosa

1974 ◽  
Vol 20 (8) ◽  
pp. 1101-1107 ◽  
Author(s):  
J. T. Tseng ◽  
L. E. Bryan
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Cell Wall ◽  
Cell Membrane ◽  
Resistant Strain ◽  
Streptomycin Resistance ◽  
Outer Cell ◽  
Similar Magnitude ◽  
Peptidoglycan Layer ◽  
Outer Cell Wall

Lysozyme-free antiserum and complement treatment of strain 1885 of Pseudomonas aeruginosa was observed to destroy the penetration barrier of the outer cell wall to lysozyme but not to induce leakage of acid-soluble nucleotides through the cell membrane. The same treatment did not produce a significant increase in uptake of 3H-tetracycline or 3H-streptomycin by the resistant strain 1885 in spite of the destruction of the penetration barrier to lysozyme. A significant increase in both streptomycin and tetracycline uptake occurred in carbenicillin-treated strains but the increase was similar for both susceptible and resistant (to tetracycline and streptomycin) strains of P. aeruginosa. These data suggest (1) the outer cell wall is not a significant penetration barrier to these drugs; (2) the peptidoglycan layer does function as a penetration barrier of similar magnitude in resistant and susceptible cells; (3) the resistance of the strains is a property of the cell membrane or materials intimately associated with the cell membrane. The latter conclusion was further supported by the differential uptake of streptomycin in NaCl-lysozyme-induced spheroplasts of strains 1885 and 2379.

In vitro studies of an alkaline phosphatase – cell wall complex from Pseudomonas aeruginosa

1975 ◽  
Vol 21 (1) ◽  
pp. 9-16 ◽  
Author(s):  
D. F. Day ◽  
J. M. Ingram
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Alkaline Phosphatase ◽  
Cell Wall ◽  
Complex Formation ◽  
Wall Material ◽  
Outer Cell ◽  
Whole Cells ◽  
Wall Components ◽  
Outer Cell Wall

Alkaline phosphatase (APase) of Pseudomonas aeruginosa exists primarily in the periplasmic region of the cell, i.e., between the cytoplasmic membrane and the outer tripartite layer. The enzyme is also found in the culture filtrate or associated with the outer layer of the cell wall. APase forms a complex with released outer cell wall material, and lipopolysaccharide (LPS) is associated with the complex. Since the enzyme was purified to homogeneity, it became desirable to determine whether complex formation with LPS, or the outer cell wall, affected any properties of the purified phosphatase. The ratio of activities of purified APase with p-nitrophenylphosphate and β-glycerolphosphate as substrates is about 4:1. The ratio of activities with enzyme complexed with LPS is about 1:1. The energy of activation of sucrose or magnesium released enzyme is 9500 cal/mol whereas the values for purified enzyme plus LPS, purified enzyme, purified enzyme plus phosphatidylethanolamine (PE), and purified enzyme plus LPS plus PE range from 3400 to 8700 cal/mol. These changes occur in the physiological temperature range, 27 to 39C, of this organism. Sucrose-released enzyme in the presence of substrate is inactivated at 47C whereas pure enzyme plus substrate is affected at 41C. The addition of LPS, PE, or a combination of both increases the temperature of inactivation from 45 to 51C. The results suggest that certain properties of the purified enzyme differ from those of the enzyme released from whole cells by either sucrose or magnesium resuspension. The addition of cell wall components such as LPS and PE to purified APase restores these properties. The evidence suggests that artificial complex formation changes the environment of the enzyme protein such that the environment now resembles that which exists within the whole cell wall.

The Outer Cell-Wall Membrane of Pseudomonas aeruginosa

1974 ◽  
Vol 130 (Supplement) ◽  
pp. S81-S93 ◽  
Author(s):  
J. C. Sadoff ◽  
M. S. Artenstein
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Cell Wall ◽  
Outer Cell ◽  
Outer Cell Wall

Outer (cell wall) membrane proteins of Pseudomonas aeruginosa

1973 ◽  
Vol 19 (12) ◽  
pp. 1469-1471 ◽  
Author(s):  
J. D. Stinnett ◽  
R. G. Eagon
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Cell Wall ◽  
Cell Envelope ◽  
Gradient Centrifugation ◽  
Sucrose Density Gradient ◽  
Outer Cell ◽  
Sucrose Density Gradient Centrifugation ◽  
Protein Components ◽  
Envelope Membranes ◽  
Outer Cell Wall

Cell envelope membranes were isolated from Pseudomonas aeruginosa. These membranes were resolved into cytoplasmic membrane rich and outer (cell wall) membrane rich fractions by discontinuous sucrose density gradient centrifugation. The resolution was based on the separation of enzyme activities and 2-keto-3-deoxyoctonate. Analysis by gel electrophoresis revealed that two of the three major cell envelope protein components were found in the fraction rich in outer (cell wall) membrane. These two protein components were previously shown to occur in a protein–lipopolysaccharide complex in this microorganism.

A freeze-etch study of plant cell walls for ectodesmata

1974 ◽  
Vol 52 (9) ◽  
pp. 2033-2036 ◽  
Author(s):  
N. C. Lyon ◽  
W. C. Mueller
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Leaf Tissue ◽  
Physicochemical Characteristics ◽  
Outer Cell ◽  
Plantago Major ◽  
Plant Cell Walls ◽  
Phaseolus Vulgaris L ◽  
Epidermal Cell Wall ◽  
Outer Cell Wall

Leaf tissue of Phaseolus vulgaris L. and Plantago major L. was prepared by the freeze-etch technique and examined in the electron microscope for the presence of ectodesmata. No structures analagous to ectodesmata observed with light microscopy could be found in freeze-etched preparations of chemically unfixed material or in material fixed only in glutaraldehyde. Objects appearing as broad, shallow, granular areas in the epidermal cell wall beneath the cuticle were observed in leaf replicas after fixation in complete sublimate fixative, the acid components of the sublimate fixative, or mercuric chloride alone. Because of their distribution and location, these objects can be considered analagous to ectodesmata observed by light microscopists. Because these areas occur only in chemically fixed walls and are localized within the walls in discrete areas, their presence supports the contention that ectodesmata are sites in the outer cell wall with defined physicochemical characteristics.

scholarly journals Spreading of a mycobacterial cell-surface lipid into host epithelial membranes promotes infectivity

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
CJ Cambier ◽  
Steven M Banik ◽  
Joseph A Buonomo ◽  
Carolyn R Bertozzi
Keyword(s):  
Cell Wall ◽  
Cell Surface ◽  
Immune Activation ◽  
Cholesterol Synthesis ◽  
Membrane Lipids ◽  
Preventive Therapy ◽  
Outer Cell ◽  
Surface Lipid ◽  
Epithelial Membranes ◽  
Outer Cell Wall

Several virulence lipids populate the outer cell wall of pathogenic mycobacteria. Phthiocerol dimycocerosate (PDIM), one of the most abundant outer membrane lipids, plays important roles in both defending against host antimicrobial programs and in evading these programs altogether. Immediately following infection, mycobacteria rely on PDIM to evade Myd88-dependent recruitment of microbicidal monocytes which can clear infection. To circumvent the limitations in using genetics to understand virulence lipids, we developed a chemical approach to track PDIM during Mycobacterium marinum infection of zebrafish. We found that PDIM's methyl-branched lipid tails enabled it to spread into host epithelial membranes to prevent immune activation. Additionally, PDIM’s affinity for cholesterol promoted this phenotype; treatment of zebrafish with statins, cholesterol synthesis inhibitors, decreased spreading and provided protection from infection. This work establishes that interactions between host and pathogen lipids influence mycobacterial infectivity and suggests the use of statins as tuberculosis preventive therapy by inhibiting PDIM spread.

scholarly journals Changes in structure of red pepper (Capsicum annuum L.) seedlings shoots under aluminum stress conditions

2012 ◽  
Vol 60 (1) ◽  
pp. 85-93 ◽  
Author(s):  
Agata Konarska
Keyword(s):  
Cell Wall ◽  
Capsicum Annuum ◽  
Red Pepper ◽  
Outer Cell ◽  
Aluminum Stress ◽  
Water Culture ◽  
Anatomical Features ◽  
Parenchyma Cells ◽  
Al Treatment ◽  
Outer Cell Wall

The seedlings of the red pepper (<i>Capsicum annuum</i> L.) cv. Trapez grown in water culture for a period of 14 days with Al (0, 10, 20 and 40 mg·dm<sup>-3</sup> AlCl<sub>3</sub>·6 H<sub>2</sub>O). Some morphological and anatomical features of red pepper shoots were analyzed. Reduction in height and diameter of stems as well as decrease in fresh mass of shoots were observed after Al-treatment. In the hypocotyl the thickness of cortex parenchyma layer and the size of their cells were reduced. The aluminum treatment resulted in the increased in thickness of the epidermis outer cell wall. Under Al stress in the cotrex and the central cylinder parenchyma cells were present numerous enlarge plastids which contained large grains of starch and dark little bodies which were possible aluminum deposits. They weren`t observed in control seedlings.

Silver nanoparticles (AgNPs) internalization and passage through the Lactuca sativa (Asteraceae) outer cell wall

2021 ◽  
Author(s):  
Sergimar Kennedy de Paiva Pinheiro ◽  
Thaiz Batista Azevedo Rangel Miguel ◽  
Marlos de Medeiros Chaves ◽  
Francisco Claudio de Freitas Barros ◽  
Camila Pessoa Farias ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Cell Wall ◽  
Lactuca Sativa ◽  
Outer Cell ◽  
Outer Cell Wall

Production of Monoclonal Antibodies Against the Outer Cell Wall ofClostridium tyrobutyricum

Hybridoma ◽  
1994 ◽  
Vol 13 (1) ◽  
pp. 45-51 ◽  
Author(s):  
FRANCOISE TALBOT ◽  
GEORGES ROBREAU ◽  
FRANCOISE GUEGUEN ◽  
ROGER MALCOSTE
Keyword(s):  
Cell Wall ◽  
Monoclonal Antibodies ◽  
Outer Cell ◽  
Outer Cell Wall

scholarly journals Conidial Hydrophobins of Aspergillus fumigatus

2003 ◽  
Vol 69 (3) ◽  
pp. 1581-1588 ◽  
Author(s):  
Sophie Paris ◽  
Jean-Paul Debeaupuis ◽  
Reto Crameri ◽  
Marilyn Carey ◽  
Franck Charlès ◽  
...  
Keyword(s):  
Cell Wall ◽  
Aspergillus Fumigatus ◽  
Amorphous Layer ◽  
Wall Layer ◽  
Host Cells ◽  
Outer Cell ◽  
Host Immune System ◽  
Wild Type ◽  
Cell Wall Layer ◽  
Outer Cell Wall

ABSTRACT The surface of Aspergillus fumigatus conidia, the first structure recognized by the host immune system, is covered by rodlets. We report that this outer cell wall layer contains two hydrophobins, RodAp and RodBp, which are found as highly insoluble complexes. The RODA gene was previously characterized, and ΔrodA conidia do not display a rodlet layer (N. Thau, M. Monod, B. Crestani, C. Rolland, G. Tronchin, J. P. Latgé, and S. Paris, Infect. Immun. 62:4380-4388, 1994). The RODB gene was cloned and disrupted. RodBp was highly homologous to RodAp and different from DewAp of A. nidulans. ΔrodB conidia had a rodlet layer similar to that of the wild-type conidia. Therefore, unlike RodAp, RodBp is not required for rodlet formation. The surface of ΔrodA conidia is granular; in contrast, an amorphous layer is present at the surface of the conidia of the ΔrodA ΔrodB double mutant. These data show that RodBp plays a role in the structure of the conidial cell wall. Moreover, rodletless mutants are more sensitive to killing by alveolar macrophages, suggesting that RodAp or the rodlet structure is involved in the resistance to host cells.

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